Hard to tell. Lots of guys like him who go young so early,fizzle earlier too. Hes pretty darn close to prime anyway
The true "prime" of an athlete is 28-31. That is when your really developed as a man, think of how much you changed from 22-30 Years of age. But hey he wants the fight, big money fight, this is the time to do it.
By the time he is in his prime he will be getting dominated by legit middleweights. So I think he is at the peak of his career.